Learning to play the piano is a complex and challenging task. Although many people can sit down at a piano and play a simple melody, it is far more daunting to learn proper piano techniques. Only a fortunate few end up really mastering the techniques necessary to play even relatively-simple musical works.
There are many well-known teaching methods used to train piano students. These include book lessons, piano methods and classroom training. In traditional music lessons, each lesson is a work in itself, i.e., a closed musical piece. The lessons form a horizontal series of single works that do not lead to a specific goal. The lessons in the series are only conceptually-related in that the lessons are grouped together based on performance difficulty such as "easy" pieces, or based on some objective such as left hand exercises or dotted sixteenth note rhythm drills. The student is expected to perform each lesson and move to the next lesson. In such training, there is little continuity between lessons besides their shared difficulty level or objective. Each lesson becomes a new beginning point for building skills because each is a closed work in itself, separate and distinct from the other lessons. As a result, a student does not specifically apply what is learned in one lesson to the next, but continues to just learn "easy" works or "left hand" drills, for example. There is only the most general transference of skill from one work to the next.
Given the rigidity of and inherent deficiencies in such prior art training methods, it is not surprising that many students give up their formal training before they acquire skills necessary to perform an original musical work. Those that still desire to play the work must typically settle on simplified versions. Some music publishers provide simplified versions or so-called "big-note" versions of musical works. This type of sheet music presents a single simplification of a work based on essentially arbitrary decisions about what the student should play. A "big-note" version is not intended to build the skills necessary to play the work it is derived from. Just like a music lesson, it is a closed musical piece that does not specifically lead to another defined work.
There is therefore a long felt need in the field of music education to provide better training tools and methodology to help build skills necessary to play musical works.